The other issue is Awakened Zero. If you take too long to beat him, he becomes invincible and starts spamming the Genmu Zero until you get hit and die in one hit. The problem is, it takes so long for it to happen (it's two song loops, but it feels like an eternity) you have to be actively trying to see it, so it might as well not be in the game anyways, it's a glorified easter egg.
If the Awakened Zero fight is made harder or longer (and it should be noticeably harder than normal Zero anyways), the Genmu Zero time limit has to be taken into account, and modified if possible/necessary.
Oh and I almost forgot, something that makes X5 stick out for inconsistency is that Zero's techs weren't left in Japanese unlike the rest of the X games. Is that going to be "undubbed"?